EASA Certification Specifications for Large Aeroplanes CS-25 Book 1 Airworthiness Code Annex to ED Decision 2008/006/R Amendment 5 CS–25 BOOK 1 1–A–1 CS 25.1 Applicability (a) This Airworthiness Code is applicable to turbine powered Large Aeroplanes. SUBPART A – GENERAL Annex to ED Decision 2008/006/R Amendment 5 CS-25 BOOK 1 GENERAL CS 25.20 Scope (a) The requirements of this Subpart B apply to aeroplanes powered with turbine engines – (1) Without contingency thrust ratings, and (2) For which it is assumed that thrust is not increased following engine failure during take-off except as specified in sub-paragraph (c). (b) In the absence of an appropriate investigation of operational implications these requirements do not necessarily cover – (1) Automatic landings. (2) Approaches and landings with decision heights of less than 60 m (200 ft). (3) Operations on unprepared runway surfaces. (c) If the aeroplane is equipped with an engine control system that automatically resets the power or thrust on the operating engine(s) when any engine fails during take-off, additional requirements pertaining to aeroplane performance and limitations and the functioning and reliability of the system, contained in Appendix I, must be complied with. CS 25.21 Proof of compliance (a) Each requirement of this Subpart must be met at each appropriate combination of weight and centre of gravity within the range of loading conditions for which certification is requested. This must be shown – (1) By tests upon an aeroplane of the type for which certification is requested, or by calculations based on, and equal in accuracy to, the results of testing; and (2) By systematic investigation of each probable combination of weight and centre of gravity, if compliance cannot be reasonably inferred from combinations investigated. (b) Reserved (c) The controllability, stability, trim, and stalling characteristics of the aeroplane must be shown for each altitude up to the maximum expected in operation. (d) Parameters critical for the test being conducted, such as weight, loading (centre of gravity and inertia), airspeed, power, and wind, must be maintained within acceptable tolerances of the critical values during flight testing. (e) If compliance with the flight characteristics requirements is dependent upon a stability augmentation system or upon any other automatic or power-operated system, compliance must be shown with CS 25.671 and 25.672. (f) In meeting the requirements of CS 25.105(d), 25.125, 25.233 and 25.237, the wind velocity must be measured at a height of 10 metres above the surface, or corrected for the difference between the height at which the wind velocity is measured and the 10-metre height. (g) The requirements of this subpart associated with icing conditions apply only if the applicant is seeking certification for flight in icing conditions. (1) Each requirement of this subpart, except CS 25.121(a), 25.123(c), 25.143(b)(1) and (b)(2), 25.149, 25.201(c)(2), 25.207(c) and (d), and 25.251(b) through (e), must be met in icing conditions. Compliance must be shown using the ice accretions defined in Appendix C, assuming normal operation of the aeroplane and its ice protection system in accordance with the operating limitations and operating procedures established by the applicant and provided in the Aeroplane Flight Manual. (2) No changes in the load distribution limits of CS 25.23, the weight limits of CS 25.25 (except where limited by performance requirements of this subpart), and the centre of gravity limits of CS 25.27, from those for nonicing conditions, are allowed for flight in icing conditions or with ice accretion. [Amdt. No.:25/3] CS 25.23 Load distribution limits (a) Ranges of weights and centres of gravity within which the aeroplane may be safely operated must be established. If a weight and centre of gravity combination is allowable only within certain load distribution limits (such as spanwise) that could be inadvertently exceeded, these limits and the corresponding weight and centre of gravity combinations must be established. (b) The load distribution limits may not exceed – (1) The selected limits; (2) The limits at which the structure is proven; or 1-B-1 Annex to ED Decision 2008/006/R Amendment 5 SUBPART B – FLIGHT CS-25 BOOK 1 (3) The limits at which compliance with each applicable flight requirement of this Subpart is shown. CS 25.25 Weight Limits (a) Maximum weights. Maximum weights corresponding to the aeroplane operating conditions (such as ramp, ground taxi, take-off, en-route and landing) environmental conditions (such as altitude and temperature), and loading conditions (such as zero fuel weight, centre of gravity position and weight distribution) must be established so that they are not more than – (1) The highest weight selected by the applicant for the particular conditions; or (2) The highest weight at which compliance with each applicable structural loading and flight requirement is shown. (3) The highest weight at which compliance is shown with the noise certification requirements . (b) Minimum weight. The minimum weight (the lowest weight at which compliance with each applicable requirement of this CS–25 is shown) must be established so that it is not less than – (1) The lowest weight selected by the applicant; (2) The design minimum weight (the lowest weight at which compliance with each structural loading condition of this CS–25 is shown); or (3) The lowest weight at which compliance with each applicable flight requirement is shown. CS 25.27 Centre of gravity limits |